Australia

In their fourth and last report from arid Australia, James and Thibaud Aronson discuss promising approaches and programs squarely facing the conservation issues that threaten western Australian ecosystems.

Nothing is simple these days: everything is subject to trade-offs. For example, take Australia’s mining industry. The country has long drawn on its enormous mineral wealth, which sustains a significant part of its economic growth. But this takes a huge toll on biodiversity. Kingsley Dixon, with whom we spent a week in the field, helped us understand the situation, and noted that the miners do not have a very good track record of cleaning up after themselves. Today, there are around 50,000 abandoned mines in Australia – sad testimony to the boom and bust pattern that seems to characterize all too many extractive industries everywhere. However, the pioneering work of Kingsley and his colleagues and students, in the areas of seed science, conservation biology, and restoration ecology, is helping advance the science and technology of restoration. This is difficult business under any circumstances, but especially so in a biodiversity hotspot. He is also extremely active in trying to persuade the mining industry and Australian government to do more and do it better in these areas.

The Mt Whaleback mine, in Western Australia, has been producing iron ore for nearly fifty years. The pit is half a kilometer deep and 5 kilometers long, and growing. Kingsley Dixon and his team are now involved in a project to restore parts of the site.

This photo, taken on the other side of the mine, shows the first step of restoration. This involves reshaping the slopes, from the steep ones seen on the right, to gentler ones on the left, which are suitable for planting. This has already cost 1 million dollars. (And, make no mistake, just about every plant growing on the slopes on the right are exotic invasives.)

Happily, despite the complexity and the obstacles, a few Australian conservation organizations are also engaged in ecological restoration – whether at the site level, or much broader scales.

Many people told us that Australians are truly proud of their unique natural heritage, and the “outback”; it only remains for the government to play a larger role, and support those who are already working towards sustainability and a restoration culture.

One of the largest players is the Australian Wildlife Conservancy (AWC), linked in a small way to the US-based organization, The Nature Conservancy (TNC). The AWC is making significant investments not only in land acquisition for conservation but also conservation research and outreach to the public.

Another example of an outstanding initiative is the 13-year old Gondwana Link, a unique and inspiring venture in the southwest. Indeed, they aim to create a biodiversity corridor 1000 km long, spanning 8 different ecosystem types. We spent several days with Keith Bradby, Chief Executive Officer of Gondwana Link, as well as Mike Griffiths, recently posted to Kalgoorlie, and veteran consultant and restoration practitioner US- born Justin Jonson, learning about the wonderfully exciting work of this coalition. They work both by acquiring pristine fragments, as well as degraded land which they restore, to provide connections between patches of habitat protected in national parks. But even more than their goals, it is their approach that is unique. Instead of coming in and telling everyone who isn’t a conservationist they they’re wrong and evil, they work with the miners, and the farmers, and the various NGOS, to achieve a vision of the landscape where humans and biodiversity can co-exist. For more information, see the chapter on Gondwana Link in Paddy Woodworth’s book Our Once and Future Planet , the first book to present the world-wide scene of ecological restoration to the general public.

The gorgeous Great Western Woodlands, near Norseman, Western Australia.

They also have a strong commitment to work with Aboriginal Traditional Owners, of both the Ngadju and Noongar peoples. Aborigines represent only 3% of the national population of 24,000,000, but finally, and bit by bit, justice is being done. Following the 1993 Native Title Act, and 18 years of shameful litigation, Aborigines are at last being granted “native title” in their own land, and control a growing percentage of Australian outback. On these recovered lands, some communities are trying to reconcile their truly ancient traditions with sound ecological management appropriate to the new lifestyles they have taken up, and the future they desire for themselves.

Another remarkable actor is the 400 – strong Australasian chapter of the Society for Ecological Restoration (SERA), led by its chair Kingsley Dixon. The challenges they face are daunting, but important and encouraging steps forward are being taken and the network is successfully raising money and doing projects. If one’s government is not helping, after all – as is the case with the current administration in Australia, social networks – of people and institutions – are the key. As we noted in our blogpost from Jordan, last April, another source of hope is the Ecological Restoration Alliance of Botanic Gardens.

To conclude, as Paul Hawken notes in Blessed Unrest,

If you look at the science that describes what is happening on earth today and aren’t pessimistic, you don’t have the correct data. If you meet people in this unnamed movement and aren’t optimistic, you haven’t got a heart.

What unnamed movement? He was referring to the thousands of independent non-governmental groups of people working for joint environmental and social change – not one or the other, but both.

As we discovered, in Australia there are plenty of clear-eyed people in conservation and restoration who do have a heart and who are working for what we would call a restoration culture for the 21st century. There: that’s a name then for the unnamed movement of this century that Hawkins referred to.

In this second report from arid Australia, James and Thibaud Aronson discuss the debated roles of fire, cattle and invasive mammals on the native fauna and flora.

To quote Gary Dinham, director of the Alice Springs Desert Park, “although the average annual rainfall in Alice Springs is just 270 mm, [9 in.], it’s erratic. For example, in 2009 the year’s total rainfall at Desert Park was 64 mm. In 2010, it was 990!”

Imagine, then, a vast region where almost no rain falls for several years, and then one year, a meter falls in two weeks, causing devastating floods. Despite the aridity, and the unpredictability, there are wooded areas in vast parts of inland Australia with annual rainfall comparable to that of Syria or Sudan! In fact, there is such a remarkable diversity of trees and shrubs, and indeed such extensive savanna or woodland tree cover, that it makes perfect sense to speak of desert canopies occurring there. However, that stunning first impression does not reveal how much the ecosystems and landscapes have been disturbed, especially in the past two centuries. How? Through severely altered fire regimes, overgrazing by domestic and feral herbivores, open-pit mining, and outrageous numbers of intentional and accidental introductions of exotic species of all sorts that really shouldn’t be there.

Because of its inordinately high biomass, the Australian center burns – or gets burned – every year or every other year…. The 70 species of spinifex grasses present throughout the arid and semiarid areas are in fact some of the most flammable plants on the planet. But that’s just part of the story.

500 meters away from where the previous photo was taken, this spot had burned six months earlier. The Eucalypts display here the unusual feature of branches resprouting high in a tree with a completely burnt trunk. What makes this possible in some few trees – including the Mediterranean cork oak – is epicormic buds. Taking advantage of the pulse of nutrients released in the soil, annuals have germinated in profusion, and spinifex will come back too, a little slower.

Because European settlers stubbornly tried to import inappropriate farming and pastoral techniques into Australia’s arid center, with its poor soils and unpredictable rainfall, they overstocked and let their cattle roam essentially freely over vast areas. Under these conditions, certain grasses and shrubs are favored, and vegetation is much more fire-prone. this has led to a large increase in the frequency of monster fires, capable of burning vast areas within days or weeks.

Even today, most landowners with cattle in the outback burn their land every single year. Why? So as to reduce fuel load, as a matter of fact, in efforts – often unsuccessful, as we’ve just said – to reduce the risk of wildfires that might burn down their houses and other infrastructure. But they also are aiming to increase the amount of palatable grasses, including the introduced Buffel grass.

Buffel grass (Pennisetum cenchroides, more commonly known by its old name Cenchrus ciliaris) by a river, showing the worst of its invasive capability, crowding out all native understory species under the canopy of red river gums (Euc. camaldulensis). Hardey River, near Paraburdoo, Western Australia.

There is little doubt that this approach could be improved on, but the truly problematic point is whether or not the desert needs to burn. That debate ultimately is rooted in divergent interpretations of the past 100,000 years of Australia’s history.

It is generally agreed that humans arrived on the island continent approximately 50,000 years ago. What is unclear is what lasting impact the first immigrants had, and on what scale. The suggested date for their arrival roughly coincides with the extinction of all animal species weighing more than 100 kg, similar to what happened later in the Americas and even later in Madagascar. Therefore, some argue that humans must have driven the megafauna to extinction. Others say that Australia had been getting progressively hotter and drier for 20 to 50 thousand years prior to the arrival of humans, and that large animals could not cope with the new climate. If that’s true, at most the earliest Australians hunted out only tiny remnant populations of these large animals (including giant kangaroos, rhinoceros-sized wombats, a lizard twice the size of a Komodo dragon, giant turtles, marsupial lions, and some of the largest birds that ever lived on Earth).

Beaten only by the ostrich, the emu (Dromaius novaehollandiae) is the second largest living bird, standing as tall as an average person. However, it is small compared to the now extinct mihurung or thunder bird (Dromornis stirtoni), that was nearly twice its size and weighed half a ton!

Through the use of ‘fire-stick farming’ (the practice of setting fires in patches to stimulate new tender shoots on grasses and other plants, and thereby attract game), the Aborigines – according to some scholars – gradually transformed most of Australia’s landscapes from fire-sensitive thickets, woodlands, and forests, to spinifex grasslands and Eucalypt woodlands highly tolerant of this kind of fire regime.

Others counter that the earliest humans in Australia in fact stayed at low population densities until the arrival of Europeans and that their nomadic societies could not possibly have transformed landscapes at any meaningful scale. To date, no clear consensus has yet emerged.

What is beyond question is the enormous impact that Europeans have had since 1788, when the first English settlers drove in their tent pegs and set up corrals for their sheep and cattle. The introduced livestock were the first animals with cloven hooves ever to walk on Australian soil. As a direct result, the biocrust, that is the beneficial communities of lichens, mosses, and bacteria which form on undisturbed soils in many arid lands, and indeed the top profiles of the soils themselves were quickly eliminated.

European settlers also cleared vast areas of land for grazing and crop lands, and introduced rabbits, cats, foxes, rats, mice, donkeys, camels, and other exotic animals which have had horrific impact on small marsupials, birds, and reptiles of the island, not to mention the complex ecological networks and community dynamics in which those animals occurred. Sad to say, Australia has the worst record of any country for recent animal extinctions.

Unsupervised cattle at a waterhole. Cockatoo Creek, Willare, Western Australia.

Cleared and overgrazed land on a cattle station in Western Australia. The ribbon of woodland in the background provides a reference for what the whole area once looked like.

Of the 60 mammal species that have gone extinct worldwide, in the last 200 years, 30 were Australian – and most inhabited the arid and semi-arid zone. Besides, a further 6 formerly widespread mammals are on the brink of extinction today, surviving only on handkerchief-sized, fenced off reserves or offshore islands inaccessible to feral cats and foxes.

While that is a terribly bleak legacy, promising steps are now being taken to limit the damage going forward, and ensure that the history of massive human-caused extinctions is not repeated. In our third and fourth blog posts from Australia we will discuss the obstacles to restoration, and then some of the encouraging endeavors underway.

James and Thibaud Aronson report from Australia, where they went to study desert trees and on-going restoration efforts.

Australia’s deserts are like no others, we found. For one thing, they have tree canopies galore and a range of habitat types that one would not expect when looking at the generally flat topography. And they are vast. Australia’s ‘dry country’ occupies 60% of its area, or more, depending on your sources, that is roughly 5 million square km (1.9 million sq mi) or over half the size of the continental US.

Map of Australia’s deserts. From Morton et al. (2011)

These huge regions stand on red or white sands with outcrops of granite, and other subtle but marvelous geomorphological jewels, and hide deep reserves of iron, copper, bauxite, uranium, and of course, gold. For two naturalists from the northern hemisphere, it’s like a candy shop: endless skies and landscapes, intriguing animals, and such an array of unique Gondwanan plants.

Very striking indeed was the remarkable diversity of trees in areas with less than 400 mm (12 in) mean annual rainfall, which is our rough and ready cutoff point for the book we are writing on dryland ecosystem restoration, with Edouard Le Floc’h. At present count, we will include at least 400 species of Australian trees, roughly a quarter of the total number of desert trees species, worldwide. But even more striking was the sheer amount of biomass in those trees and the extensive canopies they form, despite the infertile soils and highly unpredictable rainfall.

Remarkably dense woodland, away from water, in an area with 286 mm average annual rainfall. Serpentine Gorge, West MacDonnell National Park, Northern Territory.

There are few mountain ranges, perennial rivers, and drainage systems, and yet, regardless of the scale of observation, arid and semi-arid Australia is remarkably heterogeneous. These deserts are also host to a wide array of beautifully adapted animals, including the remarkable “roos”, which come in all shapes and sizes, the blue-tongued lizards, and many more.

Two common wallaroos (Macropus robustus erubescens). Cape Range National Park, Western Australia.

Galah (Eolophus roseicapilla). This cockatoo is a nomadic inland species that has greatly increased its range as a result of human land use changes. Fraser Range station, Western Australia.

One of the key areas we visited was where the desert meets the South-Western Floristic Region, which has one of the highest plant diversities on the planet, and is the only biodiversity hotspot in Australia.

This area is characterized by a large number of granite outcrops which act as fire barriers and constitute highly diversified, humid habitats with mosses, ferns and other surprises. Most remarkably, they host a significant number of both terrestrial orchids and sundews, a type of carnivorous plant, two groups we’ve never seen in arid areas anywhere before.

One of the many sundews (Drosera aff. macrantha; fide K. Dixon) found in arid Australia. Kalbarri National Park, Western Australia.

This area is what Stephen Hopper – one of the most eminent plant scientists in Australia – calls an OCBIL , an acronym for Old, Climatically Buffered, Infertile Landscapes, describing the relatively few places on Earth that for a very long time have not been rejuvenated either by orogenesis – mountain formation – or glaciation. This leads to very poor, infertile soils. Southwestern Australia, is one such place, and one that is under threat as well, given the huge pressure from the mining industry, wheat growers, pastoralists, and a government administration that seems to only think short-term.

In our next post, we will discuss a defining, and problematic process of Australian desert ecology, namely fire.